class Game(object):
    num=0 #类属性

    #实例方法
    def __init__(self):
        self.name="laowang"
    
    @classmethod
    def add_num(cls):
        cls.num=100

    @staticmethod
    def print_menu():
        print("---------------")
    

game=Game()
game.add_num()
print(game.num)

game.print_menu()